The Washburn N4 is an electric guitar model, developed in collaboration between Nuno Bettencourt, Washburn and the Seattle-based luthier Stephen Davies. Since its introduction in mid-late 1990, it became Bettencourt's primary guitar and it is marketed by Washburn as his signature model. The N4 is the flagship of the Washburn N-prefix guitar models. (N8 being an "N4 times 2" since it is a double neck guitar). Since 1990, there have been numerous versions of the N4 using various woods and hardware parts.